The difficulty in managing cooling in computer systems, servers, and electronic systems is increased as the systems evolve to more compact but higher power conditions, extending beyond simple cooling of processors to other components including memory devices. For example, memory power is increasing in systems and, when combined with an increasing number of memory sockets, thermal concerns arise when systems are configured with less than full populated memory. The concerns arise from two fundamental physical processes. First, sufficient airflow for cooling hot memory in populated sockets is bypassed when air can flow through neighboring empty memory socket channels. Second, air bypassing through empty memory bank channels creates lower pressure drop for the system. In an aggregate cooling architecture, the change in pressure drop can “steal” air from neighboring systems or components within the blade and thus cause thermal problems in various distributed areas. The thermal problems cause the fans to speed up to compensate for heating, thus using more energy and creating additional noise.
Typically, thermal and pressure drop concerns are addressed by dedicating internal fans to selected parts of the system, allowing airflow bypass for hot areas that are controlled by zones of fans that operate independently. Such a thermal control system results in less than optimal fan use, higher power usage and noise levels, and generally is sufficient only for lower power memory and stand-alone rack and tower systems.
Another thermal management technique involves insertion of “dummy” memory sticks or plastic blank partitions to fill voids, a costly solution resulting in waste since the sticks or partitions are generally discarded during upgrade. Furthermore, the technique is not thermally reliable due to lack of implementation control since the manufacturer or user may not populate the empty slots.